Vasculitis, Ischemic Dermatopathy, Panniculitis Flashcards
Breeds with familial vasculitis (all in puppies)
1) Beagles (familial necrotizing arteritis). ANCA positive.
2) GSD Familial Cutaneous Vasculopathy. Autosomal recessive. 2’ vaccination? Foot pads, nasal bridge. Self recover, but relapse with future vax.
3) Jack Russel Terrier Familial Cutaneous Vasculopathy. Vaccination? Ulcers, alopecia on boney prominences, pinnae, footpads.
4) Scottish Terrier Hereditary Vasculitis (pyogranuloma and vasculitis of the nasal planum); Autosomal dominant. Ulcer of nasal planum.
5) Shar Pei Vasculitis (life threatening! Idiopathic. Fever, hemorrhagic papules, deep ulcers, epidermal detachment. Tx GC)
Cryoglobulinemia causes
*Lead poisoning
*Upper respiratory infections
*Neoplasia (Multiple Myeloma, Lymphoma)
*Idiopathic
Systemic signs of cryoglobulinemia
*IMHA (IgM triggers it)
*Glomerulonephritis
*Thrombosis
Diagnosing cryoglobulinemia
*Immune complexes will be more severe in cold blood (refrigerator) and dissolve in warm temperature
Urticarial vasculitis causes
*Drugs
*CAFR
*Insects
*Cold
*Idiopathic
How to discern regular urticaria vs urticarial vasculitis
Vasculitic form will NOT blanch on diascopy
Normal urticaria WILL blanch on diascopy
Neonatal vasculitis pathogenesis
Foal ingesting anti-neutrophil and anti-platelet antibodies via colostrum –> forms immune complexes in their body (<4 days old) –> start bleeding.
Tx with GCs for 2 weeks. Usually a good prognosis.
Solar vasculitis skin color
Unpigmented, lightly pigmented
Often coexists with fDLE, vitiligo
Traction alopecia causes
Owners putting on cosemetic to tie the hair back (Rubber bands, Barrettes)
Traction alopecia lesions
Alopecia, thinning, scar –> well demarcated
Traction alopecia histopath
Follicular atrophy Deep arteritis (hyalinization of vessel wall)
Traction alopecia treatment
No self cure. Neglect vs pentoxifylline vs surgery
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: Breed
Racing greyhounds in USA
Many breeds in UK
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: etiology
E coli Shiga toxin (verotoxin) in raw beef
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: seasonality
Winter and summer in USA
Nov-May in the UK
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: pathogenesis
Thrombotic microangiopathy –> ischemia
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: clinical signs
Acute, with rapid deterioration
Edema, erythema –> hemorrhage, ulcers
HINDlimbs, footpads, mucosae
25% get acute kidney injury AKI. Usually AKI happens AFTER skin lesions.
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: Labwork findings
THROMBOCYTOPENIA (d/t consumption of platelets due to massive thrombosis)
AKI signs
Proteinuria, casts
Cutaneous and Renal Glomerular Vasculopathy (AKA “alabama rot”: treatment
If only skin lesions– self cure slowly, goof prognosis
Severe AKI: usually poor prognosis –> euthanize
Non-immune mediated causes of vasculitis (8)
1) Direct invasion of vascular wall (microorganisms, neoplasia)
2) Embolism (septic embolism)
3) Irradiation (UV)
4) Heat (thermal burns)
5) Water (equine immersion foot syndrome)
6) Trauma, irradiation (IV catheter)
7) Toxins
8) Hemodynamic factors (turbulence)
Immune mediated causes of vasculitis (4)
1) Immune complexes
*Antigen-antibody complexes –> complement (C3a, C5a, MAC) –> neutrophils –> granule contents, ROS released –> vasculitis
2) Anti-neutrophil cytoplasmic antibodies (ANCA)
*Ab binds to neutrophil –> activation –> granule contents, ROS released –> vasculitis
*Usual ANCA targets = neutrophil proteinase 3 & Myeloperoxidase
3) Anti-endothelial cell antibodies
4) T cells (CD8 autoreactive cells, NK cells), macrophages (ie FIP, Leishmania)
Main causes of vasculitis, general
Infection**
**Drug
*Immune-mediated dz
*CAFR
*Neoplasia
*Environmental factors (contact, heat, cold)
Proliferative (dermal) arteritis of the nasal philtrum: Breed
Saint Bernard
*Basset hound
*Bloodhound
*Dobie
*GSD
*Other large/giant breeds
Proliferative (dermal) arteritis of the nasal philtrum: Age
Mean 5 yr
Proliferative (dermal) arteritis of the nasal philtrum: Cause
Idiopathil
Familial predisposition in Saint Bernard
Proliferative (dermal) arteritis of the nasal philtrum: Clinical signs
Circular ulcer on nasal philtrum
1/3 of dogs will have PERFUSE bleeding from the lesion
Proliferative (dermal) arteritis of the nasal philtrum: Histopathology
Proliferative arteritis (deep arteries, arterioles)– Thickening of tunica media/intima: myofibroblasts that produce collagen/mucin around the arteries
Tunica interna: elastic lamina failure
Proliferative (dermal) arteritis of the nasal philtrum: Treatment
Prednisone, tacrolimus
Proliferative thrombovascular necrosis of the pinna: treatment
Oclacitinib!
Proliferative (dermal) arteritis of the nasal philtrum: etiology
Idiopathic!!
Potentially vaccination, fenbendazole
Proliferative (dermal) arteritis of the nasal philtrum: Predisposed pinnae
Pendulous, folded ears»_space; Erect ears
Proliferative (dermal) arteritis of the nasal philtrum: differential diagnoses
*Leishmania
*Bartonella henselae
*Frostbite
*Cryoglobulinemia-Cryofibrinogenemia
*Familial vasculopathies (GSD, JRT)
*Ischemic dermatopathies
Ischemic Teat Necrosis (cows): etiology
Unknown.
Usually during 1st lactation cycle of cow
LOSS OF TEATS- necrosis, self trauma
Types of Ischemic Dermatopathy (5)
1) Familial dermatomyositis
2) Dermatopmyositis-like in atypical breeds, Juvenile-onset ischemic dermatopathy
3) Post-rabies vaccine vasculitis and panniculitis
4) Generalized vaccine-associated ischemic dermatopathy
5) Adult-onset generalized idiopathic ischemic dermatopathy
Ischemic dermatopathy: histopath
Cell poor interface dermatitis
*Basal cell: Hydropic degeneration, basal cell apoptosis. Suprabasilar vesicles, ulcers
Pigmentary incontinence
*Hair follicles: Hydropic degeneration, apoptosis –> atrophy, fibrosis
*Dermis: Collagen pallor, mucinosis, edema, fibrosis
*Blood vessels: vasculitis (occasional), endothelial loss, mural hyaline changes
Ischemic dermatopathy differential diagnosis on histopath
Lupus
Familial dermatomyositis: breed
Collie (rough), Shetland sheepdog
Familial dermatomyositis: age
<6 months old for skin
Older for myositis
Familial dermatomyositis mode of inheritance
NOT mendelian inheritance (used to be thought autosomal dominance. But MANY genes!)
Familial dermatomyositis: genes
Risk alleles:
*PAN2
*MAP3K7CL polymorphisms
*MHC cl II haplotypes
Familial dermatomyositis: environmental factors
*Estrus
*Sun exposure
*Trauma
*?? virus, vaccine, drugs, toxins, stress
Familial dermatomyositis: antibody quantity
*Increased total IgG
*Increased circulating immune complexes (w/ IgG)
Familial dermatomyositis: complement related?
No difference in complement quantities in dogs
But in humans, complement deficiency is important for dermatomyositis
Familial dermatomyositis: clinical lesions, distribution
Alopecia, erythema, dyspigmentation, ulcers, scars, scale
Skin, footpads, nails; oral mucosa
Familial dermatomyositis: which muscles are involved
Masseter > skeletal
Atrophy
Dysphagia
Regurgitation
Stiff gait
Familial dermatomyositis: nail lesions
*Onychorrhexis
*Onychoschizia
*Onychomadesis
Which breed has more myositis? Collies or Shelties?
Shelties
Familial dermatomyositis: progression of disease
*Skin lesions worst at 1 year old
*Wax/wane clinical signs (stressful periods)
*May spontaneously cure, or PR
Familial dermatomyositis: how to assess muscle involvement
*CK levels (only elevated if acute flare of myositis)
*Electromyography
*Muscle biopsy (atrophy, necrosis, fibrosis, mixed inflammation)
Familial dermatomyositis: treatment
*Avoid triggers (sun, trauma; spaying if estrus trigger)
*Topical GC, tacrolimus
*Systemic GC, cyclosporine, MMP, pentoxifylline, vit E, OFA, doxycycline/niacinamide *Apoquel (works for other ischemic dermatopathies!) –> inhibition of Type 1 IFNs (which are a major cytokine for dermatomyositis)
Non-familial ischemic dermatopathies (Juvenile, adult onset, vaccine-associated [local, generalized]): signalment
*SMALL DOGS > MEDIUM DOGS
*64% of dogs are <10kg!!
*Age: all
*Chihuahua
*Toy/Mini poodle
*Maltese
*Chinese crested
*Fox terrier
*Jack russel terrier
*Yorkshire terrier
*Schipperke
*Rat terrier
Non-familial ischemic dermatopathies (Juvenile, adult onset, vaccine-associated): vaccine-associated signalment
*Toy poodle
*Young dogs
*Larger size dogs
Non-familial ischemic dermatopathies (Juvenile, adult onset, vaccine-associated): localized vaccine-associated timeline
2-3 months (up to 8 mo) after rabies vaccine
*IgG and Rabies Antigen can be found in vessels and hair follicles!!!
Non-familial ischemic dermatopathies (Juvenile, adult onset, vaccine-associated): Generalized vaccine-associated timeline
*up to 5 months after localized lesion (but don’t NEED a localized lesion first)
*C5b-9 membrane attack complex in muscle vessels
Sterile nodular panniculitis breeds
Dachshunds
Poodles
Australian shepherds
Bristtany spaniels
Chihuahuas
Dalmation
Pomeranians
Body regions for sterile nodular panniculitis
Neck, trunk
Other systemic signs that may be related to sterile nodular panniculitis
IMPA
Histo patterns of panniculitis
*Nodular
»>
*Septal
*Diffuse
*Intralobar
Treatment for sterile nodular panniculitis
*GC + 2’ immunosuppressive agent
*Needed lifelong
Only 15% achieve CR with GC monotherapy
Most common disease associated with cutaneous vasculitis in horses
Photo-aggravated dermatitis
(non-pigmented skin, normal liver enzymes, no exposure to photosensitizing agents)
BUT previous studies indicate Purpura hemorrhagica (2’ Streptococcus equi or Corynebacterium pseudotuberculosis). SQ limb edema; MM hemorrhage.
Breed with higher rate of cutaneous vasculitis in horses
Paints
Pintos
(more unpigmented skin)
Signalment with LOWER rates of cutaneous vasculitis in horses
Thoroughbreds
Stallions
Most commonly affected site for cutaneous vasculitis in horses
Legs (crust, scale, edema)
What clinical sign is indicative of a poorer prognosis in horses with cutaneous vasculitis
Fever
T or F: Vasculitis can occur 2’ PF and equine sarcoidosis
True.
Antigenic stimulation cause those 2 diseases. If antigen is similar to vascular endothelium– vasculitis will occur
OR
Antigenic stimulation causes antigen-antibody complex deposition
What type of hypersensitivity reaction occurs to trigger purpura hemorrhagica in horses
Type 3. Antibody-antigen complexes that deposit in vessel walls
Labwork findings in horses with cutaneous vasculitis
Anemia
Neutrophilia
Hyperglycemia
Hyperglobulinemia
(2’ inflammation, stress, GC administration)
T or F: Cutaneous vasculitis is likely to recur in horses
True. 44% have recurrence
Most common treatments for cutaneous vasculitis in horses
TMS
Corticosteroids
Pentoxifylline (antiinflammatory, rheological)
Factors associated with worse prognosis for ischemic dermatopathy in dogs
*<10kg
*increased age
*More lesion sites
*Systemic signs
*Pinnae, paw pad lesions
Dermatomyositis genes
MAP 3K7CL
PAN2
